Noise is a clear factor in how we perform at work. For instance, research from the Rensselaer Polytechnic Institute suggests that simply hearing sounds, such as a flowing river, can improve both our mood and also our cognitive ability.
Suffice it to say, urban environments seldom expose us to such bucolic sounds, with the hubbub of the streets a more likely inculcator than the local stream. Research from Chalmers University of Technology shows that just 40 decibels of noise can harm our cognitive performance. This is the kind of noise level often found in a typical office or kitchen.
Struggling to concentrate
Researchers from the Chalmers Division of Applied Acoustics recently conducted a laboratory study to investigate the impact of background traffic noise on concentration levels. Test subjects were asked to perform concentration tests while being exposed to simulated traffic noise. Following the tests, participants were required to assess the perceived difficulty of the task.
The study findings revealed a clear correlation between the presence of traffic noise and a decline in performance on the concentration tests. Participants exhibited significantly poorer results, indicating the detrimental effect of the ambient noise on their ability to concentrate and perform well. Moreover, participants reported a heightened sense of difficulty in carrying out the task when exposed to the background traffic noise.
“What is unique about our study is that we were able to demonstrate a decline in performance at noise levels as low as 40 dB, which corresponds to the regular noise level in an office environment or a kitchen,” the researchers explain.
Background noise
Previous research has found that the kind of background noise you get in a cafe is beneficial as it provides a sufficient level of distraction to boost our creativity. The background noise in the Swedish study consisted of a couple of audio sequences that upped the volume, however, to reflect that of a number of trucks passing close by. Both of the audio sequences were normalized to the 40 dB found in typical office environments.
“The audio sequence simulating the closer passages, where the sound changes significantly as the vehicle passes by, was usually the one that bothered the test subjects the most,” the authors continue. “This could be because traffic that is further away is perceived as a more constant drone.”
The findings highlight a growing concern regarding the negative impact of traffic noise on both health and job performance. In cities, there has been a trend of reducing the distance between residential areas and roads, a trend that is also observed internationally.
In Sweden, construction regulations are based on average outdoor noise levels over a 24-hour period, without considering individual vehicle noise. Additionally, these regulations do not address the peaks of low-frequency noise indoors, which are difficult to block out and have been found to have a greater disruptive effect on human health.
Harmful noise
The researchers demonstrated that harmful noise is mainly generated by heavy traffic moving at low speeds. Even buildings with well-insulated windows and adherence to construction norms and sound insulation guidelines struggle to effectively minimize this type of noise.
These findings reveal the shortcomings of current regulations and call for a comprehensive reassessment of noise mitigation strategies. Policymakers and urban planners need to acknowledge the urgency of addressing traffic noise’s impact on human well-being and incorporate measures that specifically target low-frequency noise. By prioritizing noise reduction and considering the unique challenges posed by low-frequency noise, a more harmonious living and working environment can be achieved for the benefit of all.
“The calculations for different types of facades show that it is difficult to achieve ideal indoor sound environments near heavily trafficked roads,” the researchers say. “Reducing speeds is not a solution, as our calculations show that the indoor noise exposure can even increase at lower speeds.”
Unequal exposure
Research from ETH Zurich highlights how exposure to this kind of harmful noise is far from equal, with lower-income people more likely to be exposed to noise pollution than their wealthier peers. They analyzed residents of Bern and Zurich in Switzerland, as well as Mainz and Hannover in Germany to compare both perceptions of noise exposure and measurements of actual exposure alongside the size and equipment of their houses.
While the analysis suggests that noise pollution is fairly evenly distributed across each of the four cities, what is not evenly distributed is the means by which people can protect themselves from the noise.
For instance, the researchers found that wealthier people often like to live in bustling neighborhoods with higher noise levels. They also tend to live in higher-quality and larger dwellings, however, and so enjoy greater protection against this noise.
“Those who earn well can afford a larger apartment and don’t have to put the bedroom on the street side,” the researchers explain. “In addition, more expensive apartments often have better windows.”
With more and more people working from home since the Covid pandemic, the impact of noise is perhaps something to keep in mind.
